docs: def llam_SI(wave, temperature):
      """Like :func:`bbfunc` but in SI units.
  
      .. note::
  
          Adapted from SSP code by Dr. Anand Sivaramakrishnan in
          IRAF STSDAS SYNPHOT.
  
      Parameters
      ----------
      wave : array_like
          Wavelength values in meters.
  
      temperature : float
          Blackbody temperature in Kelvin.
  
      Returns
      -------
      result : array_like
          Blackbody radiation in SI units.
  
      """
      exponent = C2 / (wave * temperature)
  
      result = N.zeros(wave.shape, dtype=N.float64)
  
      mask1 = N.where(exponent <= LOWER, 0, 1)
      result = N.where(mask1==0, (2.0 * C1 * (wave**-5.0)) / (exponent * (exponent + 2.0)), result)
  
      mask2 = N.where(exponent <= UPPER, 1, 0)
      mask = mask1 * mask2
      exponent = N.where(mask2==1, exponent, UPPER)
      expfactor = N.exp(exponent)
      result = N.where(mask==1, (C1 * (wave**-5.0) / (expfactor - 1.0)), result)
  
      return result